xref: /linux/arch/mips/include/asm/futex.h (revision 320fefa9e2edc67011e235ea1d50f0d00ddfe004)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (c) 2006  Ralf Baechle (ralf@linux-mips.org)
7  */
8 #ifndef _ASM_FUTEX_H
9 #define _ASM_FUTEX_H
10 
11 #ifdef __KERNEL__
12 
13 #include <linux/futex.h>
14 #include <linux/uaccess.h>
15 #include <asm/asm-eva.h>
16 #include <asm/barrier.h>
17 #include <asm/compiler.h>
18 #include <asm/errno.h>
19 #include <asm/sync.h>
20 
21 #define arch_futex_atomic_op_inuser arch_futex_atomic_op_inuser
22 #define futex_atomic_cmpxchg_inatomic futex_atomic_cmpxchg_inatomic
23 #include <asm-generic/futex.h>
24 
25 #define __futex_atomic_op(op, insn, ret, oldval, uaddr, oparg)		\
26 {									\
27 	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {	\
28 		__asm__ __volatile__(					\
29 		"	.set	push				\n"	\
30 		"	.set	noat				\n"	\
31 		"	.set	push				\n"	\
32 		"	.set	arch=r4000			\n"	\
33 		"1:	ll	%1, %4	# __futex_atomic_op	\n"	\
34 		"	.set	pop				\n"	\
35 		"	" insn	"				\n"	\
36 		"	.set	arch=r4000			\n"	\
37 		"2:	sc	$1, %2				\n"	\
38 		"	beqzl	$1, 1b				\n"	\
39 		__stringify(__WEAK_LLSC_MB) "			\n"	\
40 		"3:						\n"	\
41 		"	.insn					\n"	\
42 		"	.set	pop				\n"	\
43 		"	.section .fixup,\"ax\"			\n"	\
44 		"4:	li	%0, %6				\n"	\
45 		"	j	3b				\n"	\
46 		"	.previous				\n"	\
47 		"	.section __ex_table,\"a\"		\n"	\
48 		"	"__UA_ADDR "\t1b, 4b			\n"	\
49 		"	"__UA_ADDR "\t2b, 4b			\n"	\
50 		"	.previous				\n"	\
51 		: "=r" (ret), "=&r" (oldval),				\
52 		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
53 		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
54 		  "i" (-EFAULT)						\
55 		: "memory");						\
56 	} else if (cpu_has_llsc) {					\
57 		__asm__ __volatile__(					\
58 		"	.set	push				\n"	\
59 		"	.set	noat				\n"	\
60 		"	.set	push				\n"	\
61 		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
62 		"	" __SYNC(full, loongson3_war) "		\n"	\
63 		"1:	"user_ll("%1", "%4")" # __futex_atomic_op\n"	\
64 		"	.set	pop				\n"	\
65 		"	" insn	"				\n"	\
66 		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
67 		"2:	"user_sc("$1", "%2")"			\n"	\
68 		"	beqz	$1, 1b				\n"	\
69 		__stringify(__WEAK_LLSC_MB) "			\n"	\
70 		"3:						\n"	\
71 		"	.insn					\n"	\
72 		"	.set	pop				\n"	\
73 		"	.section .fixup,\"ax\"			\n"	\
74 		"4:	li	%0, %6				\n"	\
75 		"	j	3b				\n"	\
76 		"	.previous				\n"	\
77 		"	.section __ex_table,\"a\"		\n"	\
78 		"	"__UA_ADDR "\t1b, 4b			\n"	\
79 		"	"__UA_ADDR "\t2b, 4b			\n"	\
80 		"	.previous				\n"	\
81 		: "=r" (ret), "=&r" (oldval),				\
82 		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
83 		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
84 		  "i" (-EFAULT)						\
85 		: "memory");						\
86 	} else {							\
87 		/* fallback for non-SMP */				\
88 		ret = futex_atomic_op_inuser_local(op, oparg, oval, uaddr);	\
89 	}								\
90 }
91 
92 static inline int
93 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
94 {
95 	int oldval = 0, ret;
96 
97 	if (!access_ok(uaddr, sizeof(u32)))
98 		return -EFAULT;
99 
100 	switch (op) {
101 	case FUTEX_OP_SET:
102 		__futex_atomic_op(op, "move $1, %z5", ret, oldval, uaddr, oparg);
103 		break;
104 
105 	case FUTEX_OP_ADD:
106 		__futex_atomic_op(op, "addu $1, %1, %z5",
107 				  ret, oldval, uaddr, oparg);
108 		break;
109 	case FUTEX_OP_OR:
110 		__futex_atomic_op(op, "or	$1, %1, %z5",
111 				  ret, oldval, uaddr, oparg);
112 		break;
113 	case FUTEX_OP_ANDN:
114 		__futex_atomic_op(op, "and	$1, %1, %z5",
115 				  ret, oldval, uaddr, ~oparg);
116 		break;
117 	case FUTEX_OP_XOR:
118 		__futex_atomic_op(op, "xor	$1, %1, %z5",
119 				  ret, oldval, uaddr, oparg);
120 		break;
121 	default:
122 		ret = -ENOSYS;
123 	}
124 
125 	if (!ret)
126 		*oval = oldval;
127 
128 	return ret;
129 }
130 
131 static inline int
132 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
133 			      u32 oldval, u32 newval)
134 {
135 	int ret = 0;
136 	u32 val;
137 
138 	if (!access_ok(uaddr, sizeof(u32)))
139 		return -EFAULT;
140 
141 	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
142 		__asm__ __volatile__(
143 		"# futex_atomic_cmpxchg_inatomic			\n"
144 		"	.set	push					\n"
145 		"	.set	noat					\n"
146 		"	.set	push					\n"
147 		"	.set	arch=r4000				\n"
148 		"1:	ll	%1, %3					\n"
149 		"	bne	%1, %z4, 3f				\n"
150 		"	.set	pop					\n"
151 		"	move	$1, %z5					\n"
152 		"	.set	arch=r4000				\n"
153 		"2:	sc	$1, %2					\n"
154 		"	beqzl	$1, 1b					\n"
155 		__stringify(__WEAK_LLSC_MB) "				\n"
156 		"3:							\n"
157 		"	.insn						\n"
158 		"	.set	pop					\n"
159 		"	.section .fixup,\"ax\"				\n"
160 		"4:	li	%0, %6					\n"
161 		"	j	3b					\n"
162 		"	.previous					\n"
163 		"	.section __ex_table,\"a\"			\n"
164 		"	"__UA_ADDR "\t1b, 4b				\n"
165 		"	"__UA_ADDR "\t2b, 4b				\n"
166 		"	.previous					\n"
167 		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
168 		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
169 		  "i" (-EFAULT)
170 		: "memory");
171 	} else if (cpu_has_llsc) {
172 		__asm__ __volatile__(
173 		"# futex_atomic_cmpxchg_inatomic			\n"
174 		"	.set	push					\n"
175 		"	.set	noat					\n"
176 		"	.set	push					\n"
177 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
178 		"	" __SYNC(full, loongson3_war) "			\n"
179 		"1:	"user_ll("%1", "%3")"				\n"
180 		"	bne	%1, %z4, 3f				\n"
181 		"	.set	pop					\n"
182 		"	move	$1, %z5					\n"
183 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
184 		"2:	"user_sc("$1", "%2")"				\n"
185 		"	beqz	$1, 1b					\n"
186 		"3:	" __SYNC_ELSE(full, loongson3_war, __WEAK_LLSC_MB) "\n"
187 		"	.insn						\n"
188 		"	.set	pop					\n"
189 		"	.section .fixup,\"ax\"				\n"
190 		"4:	li	%0, %6					\n"
191 		"	j	3b					\n"
192 		"	.previous					\n"
193 		"	.section __ex_table,\"a\"			\n"
194 		"	"__UA_ADDR "\t1b, 4b				\n"
195 		"	"__UA_ADDR "\t2b, 4b				\n"
196 		"	.previous					\n"
197 		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
198 		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
199 		  "i" (-EFAULT)
200 		: "memory");
201 	} else {
202 		return futex_atomic_cmpxchg_inatomic_local(uval, uaddr, oldval, newval);
203 	}
204 
205 	*uval = val;
206 	return ret;
207 }
208 
209 #endif
210 #endif /* _ASM_FUTEX_H */
211